Sub joins MH370 hunt ahead of Malaysian PM visit to Perth

The protracted search for missing Flight MH370 was boosted Wednesday with the arrival of a British nuclear submarine in the Indian Ocean, ahead of a visit to Australia by Malaysian Prime Minister Najib Razak.

The personal jet of Oscar-winning New Zealand movie director Peter Jackson is also now reportedly being used in the multinational hunt for the plane that vanished on March 8 with 239 people on board.

Despite extensive scouring of remote Indian Ocean waters by planes and ships southwest of Perth where Malaysia believes the jet went down, nothing has been found so far that would indicate a crash site.

"No significant developments to report," the Australian Maritime Safety Authority tweeted after 10 planes returned from flying sorties on Tuesday evening in a now familiar update on drawing a blank.

But in a boost to the search effort, Britain's Royal Navy said the first submarine in the operation -- HMS Tireless -- has arrived in the area and "with her advanced underwater search capability will be able to contribute to the attempts to locate the missing plane".

Britain's HMS Echo is also due in the search zone shortly to assist Australia's Ocean Shield naval vessel, which is fitted with a US-supplied "black box" detector and is expected to arrive on Friday.

Jackson, the director of the "Lord of the Rings" and "The Hobbit" movies, has personally approved the use of his Gulfstream G650 in the search, Radio New Zealand said.

His spokesman reportedly said the company which operates the long-range aircraft had chartered it to Australian authorities.

The battery-powered signal from MH370's black box -- which records flight data and cockpit voice communications that could indicate what happened -- usually lasts only about 30 days, with time fast running out to find it.

Australia has warned against expectations of quick success in the difficult task of recovering the black box from the deep and vast seas.

Retired Australian air chief marshal Angus Houston, who is heading a new coordination centre in Perth, reiterated Wednesday that the odds were stacked against them.

"The reality is it's the most complex and challenging search and recovery operation I've ever seen," he told national radio.

"We have to keep searching and searching with vigour, because what's really vital here is to find some wreckage, some debris on the surface of the ocean.

"It's only through that that we'll hopefully lead to where the aircraft is on the bottom of the ocean."

Najib due in PerthMalaysian Prime Minister Najib is due in Perth on Wednesday evening to tour the air base being used as a staging post and meet with his Australian counterpart Tony Abbott, as well as Houston.

Malaysia's handling of the crisis, marked by piecemeal and occasionally contradictory information, has been widely questioned, especially by distraught relatives of the 153 Chinese nationals aboard.

Many of them have alleged incompetence or even a cover-up by Malaysia, straining ties between the two countries, although the rhetoric has eased in recent days.

Despite this, Houston said: "The cooperation with Malaysia has been first class."

In an effort to appease angry relatives, a closed-door briefing is scheduled for Wednesday in Kuala Lumpur with families of those who were on board the plane to hear from technical experts from Malaysia, China and Australia.

On Tuesday, Malaysia Airlines revealed the full radio communications with the pilots of MH370, but the routine exchanges shed no light on the mystery.

The conversations with air traffic controllers had been the subject of much speculation as suspicions have focused on whether one or both of the pilots deliberately diverted the plane.

"There is no indication of anything abnormal in the transcript," a Malaysian government statement said of the 43 separate transmissions over nearly 54 minutes.

Malaysia's authoritarian government -- which muzzles its own pliant mainstream press -- revealed it was compiling a dossier of "false" media reports over the crisis and would consider filing lawsuits.

Transport and Defence Minister Hishammuddin Hussein said on his Twitter feed that the country's attorney general had been instructed to "compile evidence and advise" on possible legal action.